I have outlander 3.0L 2009, when start AC it will be cooling normally. But after some time (it varies), no cooling and I can feel that compressor not engaged.
Mechanic requested me to change comoressor, but I fell it is not an issue in the compressor
How can I verify the mechanic advise?

 

find out what the psi is on the high side and low side, you can over charge a system, whereby once things get hot, the psi sensor prevents further psi from being built up but refusing to engage the compressor, but when cooled down, the psi is back in the correct range, if the mechanic hasn't even mentioned how they've diagnosed a bad compressor, you may want a 2nd opinion, I have only topped my refrigerant off 2 times in 13 years and it blows cold as ever, even in the desert

 

My 2010 Outlander A/C is not as cool it used to be. Did you use A/C Pro to top off the refrigerant? R134a?